Earlier we got this, ICYMI:
CFTC orders FXCM to pay $7M penalty for defrauding retail forex customers
The gist is FXCM got into trouble for:
 FXCM engaged in false and misleading solicitations of FXCM’s retail foreign exchange (forex) customers by concealing its relationship with its most important market maker and by misrepresenting that its "No Dealing Desk" platform had no conflicts of interest with its customers.